Five Boko Haram commanders were released in exchange for the freedom of 82 Chibok schoolgirls kidnapped by the extremist group three years ago, a Nigerian government official said Sunday, as the girls were expected to meet with the country’s president and their families.

The confirmation of the prisoner swap came a day after the young women were liberated. The official spoke on condition of anonymity as he was not authorized to speak to reporters on the matter.

There was no immediate comment about the exchange from the Nigerian presidency or Boko Haram, which has links to the Islamic State group. President Muhammadu Buhari’s office said Saturday that “some” Boko Haram suspects in detention had been released for the freedom of the schoolgirls, but it did not give details.

The young women were flown Sunday by military helicopters from northeastern Nigeria to Abuja, the capital, where they were expected to meet the president in the evening.

The International Committee of the Red Cross, which along with the Swiss government mediated the Nigerian government’s negotiations with Boko Haram, said Sunday that the girls soon would meet with their families.

The Rev. Enoch Mark, whose two daughters have been among the missing, was still waiting word if they were among those freed. He emphasized though that he considered all 82 of the girls to be his daughters “because most of them worship in my church.”

“Three years is not three days,” he said. “I have to be anxious with the intention to see if one of my daughters is among the released ones.”

Some parents did not live long enough to see their daughters released, underscoring the tragedy of the three-year-long saga. And the recovery process is expected to be a long one for the girls, many of whom endured sexual assault during their time in captivity.

“They will face a long and difficult process to rebuild their lives after the indescribable horror and trauma they have suffered at the hands of Boko Haram,” said Pernille Ironside, acting representative of UNICEF Nigeria.

Authorities say 113 schoolgirls remain missing from the group of 276 abducted from their boarding school in April 2014. Girls who escaped early on said some of their classmates had died from illness. Others did not want to come home because they’d been radicalized by their captors, they said.

Human rights advocates also fear some of the girls kidnapped from the Chibok boarding school have been used by Boko Haram to carry out suicide bombings.

Last year, a first group of 21 Chibok girls was freed in October, and they have been in government care in Abuja for medical attention, trauma counseling and rehabilitation. Human rights groups have criticized the decision to keep the girls in custody in Abuja, nearly 900 kilometers (560 miles) from Chibok.

It was not immediately clear whether the newly freed girls would join them.They should be quickly released to their families and not be subjected to lengthy government detention, Amnesty International’s Nigeria office said, adding that the girls don’t deserve to be put through a “publicity stunt” and deserve privacy.

Though Boko Haram has abducted thousands of people during its eight-year insurgency that has spilled across Nigeria’s borders, the Chibok mass kidnapping in 2014 horrified the world and brought the extremist group international attention.

The failure of Nigeria’s former government to act quickly to free the girls sparked a global Bring Back Our Girls movement; U.S. first lady Michelle Obama posted a photo with its logo on social media.

The Bring Back Our Girls campaign said Sunday it was happy that Nigeria’s government had committed to rescuing the 113 remaining schoolgirls.

“We urge the president and his government to earnestly pursue the release of all our Chibok girls and other abducted citizens of Nigeria,” the group said in a statement.

Buhari late last year announced Boko Haram had been “crushed,” but the group continues to carry out attacks in northern Nigeria and neighboring countries. Its insurgency has killed more than 20,000 people and driven 2.6 million from their homes, with millions facing starvation.